Apparatus for making cores



March 29, 1938. F. G. scHULTz l APPARATUS FOR MAKING CORES Filed June l5, 1956 l. Arma u WN rllll.

QN. HNI

YPatented Mar. 29, 193s UNITED STATI-:s

PATENT oFFIcE 1 Claim.

This invention relates particularly to the manufacture of sand cores, but the principles thereof are equally applicable to analogous arts involving molding and drying or baking operations, and while the invention will be described in detail with reference to its application to the manufacture of cores, it may be utilized in other ways.

'Ihe present practice in the core department of a foundry is to provide a single oven for baking all types and sizes of cores. The molders benches are located wherever convenient, at varying distances from the oven. This necessitates that the cores be transported from the points at which they are molded to the oven for baking. This arrangement is not eiiicient for a number of reasons. In the iirst place, a large amount of iioor space is required and considerable time is lost by the workmen in transferring the cores to the oven. The oven must be of sufcient size to handle capacity production, but is not economical to operate when running on low production schedules. All cores, regardless of their size or character, are subjected to the same baking treatment. Considerable heat is lost in charging and unloading the oven, and this makes for adverse working conditions adjacent the oven.

I have invented a novel method and apparatus for making cores which avoids the aforementioned objections to the present practice, and is characterized by additional features of novelty and advantage which will become apparent in the course of the detailed description and be specifically pointed out in the appended claim.

In accordance with my invention, I provide a unit type of oven having a molders bench incorporated therein, together with means for transporting cores from the bench in which they are molded, to the desired point of use. The units are of such construction that they are adapted to be placed side by side, in any desired number. Each oven is heated independently of all the others so that it is unnecessary to iire more than the exact number of ovens needed when running on low production schedules. In addition, there is no time lost by the core maker in taking the cores from his bench to the oven. 'I'he ovens are preferably double-ended so that a molder can operate on either side of the line of unit ovens. I provide means for cutting off outflow of heat from the oven when the door is open for loading or unloading. 'Ihe unit type of construction permits each class of cores to be subjected to precisely the desired baking conditions so that over or under baking may be avoided.

A present preferred embodiment of the invention is illustrated in the accompanying drawing which is, however, illustrative only and not-intended to restrict the scope of the invention or the manner in which it may be practiced.

In the drawing,

Fig. 1 is a side elevation showing one unit and a portion of another in cooperative relation therewith;

Fig. 2 is a vertical sectional View along the line II-II of Fig. 1; and

Fig. 3 is a horizontal sectional view along the line III-III of Fig. 1.

As shown in the drawing, an oven I0 comprises spaced inner and outer walls II and I2. The walls I2 dene an inner chamber I3 and may be Supported within the` outer walls II in .any convenient manner. Insulation I4 is 'applied to the inner and outer walls, leaving an air space therebetween. A working or molding surface I 5 is provided on topof the oven III. A conveyor section I6 is supported thereabove by brackets I1. Tool drawers I8 are slidably suspended below the conveyor section, one drawer being accessible on each side of the oven. The construction is such as to permit molding operations to be carried on simultaneously by two men, one on each side of the unit oven.

Openings I9 and 20 in the outer and inner walls are adapted to be closed by doors 2| and 22 hinged to the outer and inner walls respectively. d

A work-supportingk shelf 23 is carried jointly by the doors 2| and 22. Ihe shelf has a pin and slot connection to a bracket 24 carried on the door 22. The door 2I has a closure 25 adapted to overle the opening 20 when the door 2I is closed. The closure 25 has a sealing gasket 26 and is yieldably mounted on the door 2|, having back-up springs 2'I for urging it into position when the door 2| is closed. 'I'he shelf 23 may be attached to the closure 25 in any desired manner, preferably so that it can be removed if desired.

By virtue of the connection between the doors 20 and 2l provided by the shelf 23, the door 22 swings shut as the door 2I is opened, and vice versa. This prevents escape of heat from the oven while loading and unloading the shelf 23, and prevents discomfort to the molder. A manually operable locking handle 28 keeps the outer door closed during the baking operation.

The oven I0 may be heated by any convenient means, such as electric resistors, gas or oil burners. Since such devices are well known, I have not illustrated them in detail. It will be understood that if the oven is to be heated by fuel ring, an outlet vent for exhaust gases will be required in addition to the burner. This outlet may be placed wherever convenient.

Pull-out shelves 29 slidably mounted o-n opposite sides of the oven provide additional working space.

According to the method for practice of which the apparatus above described is particularly designed, the workman molds the cores on the bench I5 on which the molding material may be stored. When enough cores have been made to fill the shelf space in the oven, the door 2l is unlatched and swung open. This closes the door 22 and exposes the shelf 23 for loading. In addition tothe shelf 23, a second shelf (not shown) may be removably swung between brackets 30 mounted on the doors 2| and 22. The shelves may then be loaded with cores, without loss of heat from the oven or exposure of the molder to the heat of the oven. The door 2| may then be closed and the cores baked for the proper length of time. After baking, the cores are removed. They are generally, placed on trays for convenient handling after molding, and the trays may be deposited on the conveyor I6 and pushed therealong in the direction of the point of use. The molder will also keep other trays fed toward his bench from adjoining units, moving in the saine direction.

The double-wall construction with insulating layers and a dead air space therebetween prevents substantial loss of heat from the oven when the outer door is closed, and the inner door prevents loss of heat when the outer door is open.

The unit type molding bench and oven described above is characterized by numerous advantages over the existing practice of molding and baking cores. Since the ovens are of the unit type, they may be individually controlled to provide proper baking for each individual size or class of core being made, and only as many ovens need be kept in operation as are required for current production. The baking of the cores at the location where they are molded saves the time heretofore consumed in transporting the cores from the point of molding to the oven. The continuous conveyor permits ready delivery of the baked cores to `the point of use. Working conditions are improved because little or no heat escapes from the ovens into the working spaces on each side thereof. The floor space required for a given production volume is reduced, and the actual output per man is increased because a greater proportion of the molders time is devoted to actual molding. Increased production demand may be satisfied simply by installing additional units. All the work involved in making finished cores is concentrated within a small area, thus avoiding loss of time.

While the invention has been illustrated and described as applied to the molding and baking of cores for foundry molds, I wish to make it plain that it may also be applied to other articles or processes involving similar steps, viz., molding and heating or drying. In the following claim, therefore, I intend that the term core be construed not as a word of limitation, but as indicative of any member of the class of articles analogous thereto.

Although `I have illustrated and described in detail but one preferred embodiment and practice of the invention, it will be understood that various changes in the construction and procedure disclosed may be made without departing from the spirit of the invention or the scope of the following claim.

I claim:

As a new article of manufacture, a combined core bench and oven having a flat top providing a working surface accessible to coremakers standing on opposite sides of the bench, side and end walls extending downwardly from said top and defining a core baking oven, and a conveyor section extending longitudinally above and supported on the bench substantially midway of said surface whereby it is accessible equally to the coremakers on both sides thereof, said conveyor section being so mounted on the bench as to line up with similar sections of adjacent benches disposed in end-to-end relation therewith, to facilitate movement of cores from said bench to a point of delivery, and doors in said side walls affording access to said oven from both sides of said bench.

FERDINAND G. SCI-IULTZ. 

